Aluminum alloy electrical conductor

ABSTRACT

Aluminum alloy electrical conductors are produced from aluminum base alloys containing from about 0.20% to about 1.60% by weight cobalt, about 0.30% to about 1.30% nickel, optionally up to about 2.0% of additional alloying elements, and from about 97.0% to about 99.5% by weight aluminum. The alloy conductors have an electrical conductivity of at least 57%, based on the International Annealed Copper Standard (IACS), and improved properties of increased thermal stability, tensile strength, percent ultimate elongation, ductility, fatigue resistance and yield strength as compared to conventional aluminum alloys of similar electrical properties.

Schoerner et al.

[451 Apr. 30, 1974 ALUMINUM ALLOY ELECTRICAL CONDUCTOR [75] Inventors: Roger J. Schoerner; Enrique C.

Chia, both of 'Carrollton, Ga.

[73] Assignee: Southwire Company, Carrollton,

[22] Filed: Dec. 1, 1970 [21] Appl. No.: 94,177

Related US. Application Data [63] Continuation-impart of Ser. No. 54,563, July '13,

1970, abandoned.

[52] US. Cl 29/193, 29/5277, 75/138, v 148/2, l48/1l.5 A, 148/32, 164/76 [51] Int. Cl. B2lc -1/00, C22f 1 /04 [58] Field of Search 75/138-148; .148/32, 32.5,2, 11.5 A; 29/193, 193.5, 527.7; 164/76 [56] References Cited UNITED STATES PATENTS 3,160,513 12/1964 Westerveld et al. ..1 17/35 1,579,481 4/1926 Hybinette 1,916,087 6/1933 Titus 75/147 1,945,297 l/1934 .-Stemer- Rain'e r 75/147 2,245,166 6/1941 Stroup 75/147 FOREIGN PATENTS ORAPPLICATIONS 498,227 1/1939 Great Britain OTHER PUBLICATIONS Krupotkin et al., The Mechanical Properties of AVOOO Aluminum with small additions of Different Elements, Metals Abstract, December, 1969, 312291.

France Krupotkin, Influence of Small Additions of Iron,

Nickel and Cobalt on Mechanical Properties and Conductivity of Aluminum, Slavic Library, Nov. 30, 1965, Battell Memorial Institute.

Primary Examiner-Richard 0. Dean Attorney, Agent, or Firm-Herbert M. Hanegan; Van C. Wilks {57] ABSTRACT Aluminum alloy electrical conductors are produced from aluminum base alloys containing from about 0.20% to about 1.60% by weight cobalt, about 0.30% to about 1.30% nickel, optionally up to about 2.0% of additional alloying elements, and from about 97.0% to about 99.5% by weight aluminum. The alloy conductors have an electrical conductivity of at least 57%, based on the International Annealed Copper Standard (IACS), and improved properties of increased thermal stability, tensile strength, percent ultimate elongation, ductility, fatigue resistance and yield strength as compared to conventional aluminum alloys of similar electrical properties.

26 Claims, No Drawings 1 ALUMINUM ALLOY ELECTRICAL CONDUCTOR CROSS-REFERENCE TO RELATED APPLICATION This application is a continuation-impart of our copending application Ser. No. 54,563, filed July 13, 1970, now abandoned.

The present invention concerns an aluminum base alloy especially suited for producing high strength lightweight electrical conductors including wire, rod and other such articles of manufacture. The present'alloy is particularly well suited for use as a wire, rod, cable, bus bar, tube connector, termination, receptacle plug, or electrical contact device for conducting electricity.

Aluminum base alloys are finding wider acceptance in the marketplace of today because of their light weight and low cost. One area where aluminum alloys have found increasing acceptance is in the replacement of copper in the manufacture of electrically conductive wire. Conventional electricallyconductive aluminum alloy wire (referred to as EC) ,containsa substantial amount of purealuminum and trace amounts of impurities such as silicon, vanadium, iron, copper, manganese, magnesium, zinc, boron, and titanium.

Even though desirable in terms of weight and cost, aluminum alloys have received far less than complete acceptance in theelectrical conductor marketplace. One of the chief reasons for .the lack of complete acceptance is the range of physical propertiesavailable with conventional EC aluminum alloy conductors. 1f the physical properties, such as thermal stability, tensile strength, percent elongation, ductility and yield strength, could be improved significantly without sub- -stantially lessening the electrical conductivity of the suitable results are not obtained if the maximum percentages for all alloying elements are employed. If

finished product, a very desirable improvement would be achieved. It is accepted, however, that addition of alloying elements, as in other aluminum alloys, reduces conductivity while improving the physical properties. Consequently, only those additions of elements which improve physical properties without substantially lessening conductivity will yield an acceptable and useful product.

It is an object of the present invention, therefore, to

provide a new aluminum alloy electrical conductor which combines improved physical properties with acceptable electrical conductivity. These and other objects, features and advantages of the present invention will be apparent from a consideration of the following detailed description of an embodiment of the invention.

In accordance with the invention, the present aluminum base alloy is prepared by mixing cobalt, nickel'and optionally other alloying elements with aluminum in av furnace to obtain a melt having requisite percentages of elements. It has been found that suitable results are obtained with cobalt present in a weight percentage of about 0.20% to about 1.6%. Superior results are achieved when cobalt is present in a weight percentage of about 0.5% to about 1.0% and particularly superior and preferred results are obtained when cobalt is present in a percentage by weight of about 0.6% to about 0.8%. 1

Suitable results are obtained with nickel present in a weight percentage of about 0.3% to about 1.3%. Superior results are achieved when nickel is present in a weight percentage of 0.4% to about 0.8% and particucommercial aluminum is employed in preparing the present melt, it is preferred that the aluminum, prior to addingto the melt in the furnace, contain no more 0.1% total of trace impurities.

Optionally the present alloy may contain an additional alloying element or group of alloying elements. The total concentration of the optional alloying elements may be up to 2.0% by weight; preferably from about 0.1% to about 1.5% by weight is employed. Particularly superior and preferred results are obtained when 0.1% to about 1.0% by weight of total additional alloying elements is employed.

Additional alloying elements include the following:

ADDITIONAL ALLOYING ELEMENTS Magnesium Scandium Terbium Iron Thorium Erbium Copper Tin Neodymium Silicon Molybdenum Indium Zirconium Zinc Boron Cerium Tungsten Thallium Niobium Chromium Rubidium Hafnium Bismuth Titanium Lanthanum Antimony Carbon Tantalum Vanadium Cesium Rhenium Yttrium Dysprosium Superior results are obtained with the following additional alloying elements in the percentages, by weight, as shown:

PREFERRED ADDITIONAL ALLOYlNG ELEMENTS Magnesium 0.001 to 1.0% lron 0.001 to 1.0% Copper 0.05 .to 1.0% Silicon 0.05 to 1.0% Zirconium 0.01 to 1.0% Niobium 0.01 to 2.0% Tantalum 0.01 to 2.0% Yttrium 0.01 to 1.0% Scandium 0.01 to 1.0% Thorium 0.01 to 1.0% Rare Earth Metals 0.01 to 2.0%

Carbon 0.01 to 1.0%

or total group, the total percentage of the group being within the percentage range stated previously.

It should be understood that the additional alloying elements may be present either individually or as a group of two or more of the elements. It should be understood, however, that if two or more of the additional alloying elements are employed, the total concentration of additional alloying elements should not exceed 2.0% by weight. I

After preparing the melt, the aluminum alloy is preferably continuously cast into a continuous bar by a continuous casting machine and then, substantially immediately thereafter, hot-worked in a rolling mill to yield a continuous aluminum alloy rod.

One example of a continuous casting and rolling operation capable of producing continuous rod as specified in this application is contained in the following paragraphs. It should be understood that other methods of preparation may be employed to obtain suitable results but that preferable results are obtained with continuous processing. Such other methods include conventional extrusion and hydrostatic extrusion to obtain rod or wire directly, sintering an aluminum alloy pow der to obtain rod or wire directly, casting rod or wire directly from a molten aluminum alloy, and conventional casting of aluminum alloy billets which are subsequently hot-worked to rod and drawn with intermediate anneals into wire.

CONTINUOUS CASTING AND ROLLING OPERATION A continuous casting machine serves as a means for solidifying the molten aluminum alloy metal to provide a cast bar that is conveyed in substantially the condition in which it solidified from the continuous casting machine to the rolling mill, which serves as a means for hot-forming the 'cast bar into rod or another hotformed product in a manner which imparts substantial movement to the cast bar along a plurality of angularly disposed axes.

The continuous casting machine is of conventional casting wheel type having a casting wheel with a casting groove in its periphery which is partially closed by an endless belt supported by the casting wheel and an idler pulley. The casting wheel and the endless belt cooperate to provide a mold into one end of which molten metal is poured to solidify and from the other end of which the cast bar is emitted in substantially that condition in which it solidified.

The rolling mill is of conventional type having a plurality of roll stands arranged to hot-form the cast bar by a series of deformations. The continuous casting machine and the rolling mill are positioned relative to each other so that the cast bar enters the rolling mill substantially immediately after solidification and in substantially that condition in which it solidified. In this condition, the cast bar is at a hot-forming temperature within the range of temperatures for hot-forming the cast bar at the initiation of hot-forming without heating between the casting machine and the rolling mill. In the event that it is desired to closely control the hotforming temperature of the cast bar within the conventional range of hot-forming temperatures, means for adjusting the temperature of the cast bar may be placed between the continuous casting machine and the rolling mill without departing from the inventive concept disclosed herein.

The roll stands each include a plurality of rolls which engage the cast bar. The rolls of each roll stand may be two or more in number and arranged diametrically opposite from one another or arranged at equally spaced positions about the axis of movement of the cast bar through the rolling mill. The rolls of each roll stand of the rolling mill are rotated at a predetermined speed by a power means such as one or more electric motors and the casting wheel is rotated at a speed generally determined by its operating characteristics. The rolling mill serves to hot-form the cast bar into a rod of a crosssectional area substantially less than that of the cast bar as it enters the rolling mill.

The peripheral surfaces of the rolls of adjacent roll stands in the rolling mill change in configuration; that is, the cast bar is engaged by the rolls of successive roll stands with surfaces of varying configuration, and from different directions. This varying surface engagement of the cast bar in the roll stands functions to knead or shape the metal in the cast bar in such a manner that it is worked at each roll stand and also to simultaneously reduce and change the cross-sectional area of the cast bar into that of the rod.

As each roll stand engages the cast bar, it is desirable that the cast bar be received with sufficient volume per unit of time at the roll stand for the cast bar to generally fill the space defined by the rolls of the roll stand so 4 that the rolls will be effective to work the metal in the cast bar.- However, it is also desirable that the space defined by the rolls of each roll stand not be overfilled so that the cast bar will not be forced into the gaps between the rolls. Thus, it is desirable that the rod be fed toward each roll stand at a volume per unit of time which is sufficient to fill, but not overfill, the space defined by the rolls of the roll stand.

As the cast bar is received from the continuous casting machine, it usually has one large flat surface corresponding to the surface of the endless band and inwardly tapered side surfaces corresponding to the shape of the groove in the casting wheel. As the cast bar is compressed by the rolls of the roll stands, the cast bar is deformed so that it generally takes the crosssectional shape defined by the adjacent peripheries of the rolls of each roll stand.

Thus, it will be understood that with this apparatus, cast aluminum alloy rod of an infinite number of different lengths is prepared by simultaneous casting of the molten aluminum alloy and hot-forming or rolling the cast aluminum bar. The continuous rod has a miniumum electrical conductivity of 57% IACS and may be used in conducting electricity or it may be drawn to wire of a smaller cross-sectional diameter.

To produce wire of various gauges, the continuous rod produced by the casting and rolling operation is processed in a reduction operation. The unannealed rod (i. e., as rolled to f temper) is cold-drawn through a series of progressively constricted dies, without intermediate anneals, to fonn a continuous wire of desired diameter. It has been found that the elimination of intermediate anneals is preferable during the processing of the rod and improves the physical properties of the wire. Processing with intermediate anneals is acceptable when the requirements for physical properties of the wire permit reduced values. The conductivity of the hard-drawn wire is at least 58% IACS. If greater conductivity or increased elongation is desired, the wire may be annealed or partially annealed after the desired wire sizeis obtained and cooled. Fully annealed wire has a conductivity of at least 59% lACS. At the conclusion of the drawing operation and optional annealing operation, it is found that the alloy wire has the propercept in those cases where the alloying elements are known carbide formers, in which cases aluminum oxide crucibles are used. The melts are held for sufficient times and at sufficient temperatures to allow complete A more complete understanding of the invention will be obtained from the following examples:

EXAMPLE NO. 1

der being aluminum. Graphite crucibles are used exties of improved tensile strength and yield strength to- 5 solubility of the alloying elements with the base alumigether with improved thermal stability, percent ultinum. An argon atmosphere is provided over the melt mate elongation and increased ductility and fatigue reto prevent oxidation. Each melt is continuously cast on sista'nce as specified previously in this application. The a continuous casting machine and immediately hotannealmgoperatlon may be continuous as in resistance rolled through a rolling mill to inch continuous rod. annealing, induction annealing, convection annealing 10 Wire is then drawn from the rod in both the as-rolled by continuous furnaces or radiation annealing by conc nditi (h d d) d f b i l d for 5 tmuous furnaces, p a y, y be batch hours at 650F (soft rod). The final wire diameter obnealed in a batch furnace. When continuously annealtained is 0.107 inches, 10 gauge AWG. Wire from each g, temperatures of a ut 50 F to ab ut l,200F type rod is tested in both the as-drawn condition (hard may be employed w1th annealing times of about live wire) .and after being annealed for 5 hours at 650 F minutes to about 1/ 10,000 of aminute. Generally, how- (soft wire), ever, continuous annealing temperatures and times The types of alloys employed and the results of the may be adjusted to meet the requirements of the partictests performed thereon are as follows:

TABLE l C0 Fe Mg Ni HR SR HW-HR HW-SR SW-HR SW-SR Properties .80 .08 .80 2.1 27.5 1.7 25.1 Elong.

29,400 15,900 34,700 15,870 UTS 62.62 60.06 59.56 60.47 lACS .30 .10 .90 1.2 21.0 2.2 2.3 22.7 23.0 Elong.

29,400 16,040 40,530 33,300 17,450 16,700 UTS 59.34 59.75 58.l4 5M1 59.95 60.01 lACS .40 .80 .10 .40 2.8 20.0 2.0 2.5 22.9 24.5 lilong. 30.340 17.110 37,935 32,500 l8,35() 17,245 u'1's 59.19 60.65 58.64 59.66 60.65 60.72 %1Acs HR Hard RDd SR Soft Rod HW-HR Hard wirc drawn from Hard Rod HW-SR Hard Wire drawn from Soft Rod SWHR Soft Wire drawn from Hard Rod SW-SR Soft .Wire drawn from Soft Rod Elong. Percent ultimate elongation UTS Ultimate Tensile Strength lACS Conductivity in Percentage lACS ular overall processing operation so long as the desired 40 Soft wire and soft rod are the fully annealed forms of physical properties are achieved. In a batch annealing the products. operation, a temperature of approximately 400 F to EXAMPLE NO about 750 F is employed with residence times of about 30 minutes to about 24 hours. As mentioned with readdltlonal alloy melt p p f f aPcordmg to spect to continuous annealing, in batch annealing the ample 1 so that the composltlon 15 as follows times and temperatures may be varied to suit the over- Weight Percent? all process so long as the desired physical properties are obtained. 1

It has been found that the properties of a Number 10 $1111, 828% gauge (American wire gauge) fully annealed soft wire g e i of the present alloy vary between the following figures: mmum The melt is processed to a No. 10 gauge soft wire from Tensile 7, Yield hard rod. The physical properties of the wire are as fol Conductivity Strength, psi. Elongation Strength, psi. l w

Ultimate Tensile Strength 18,800 psi Percent Ultimate Elongation 2l% Conductivity 59.05% lACS EXAMPLE No. 3

Cobalt Nickel Misch Metal Aluminum Misch metal is a commercial designation for a blend of Cobalt 0.80% Nickel 0.45% Zirconium 0.30% Aluminum Remainder rare earth metals and Thorium obtained during the pro- Th 1fi processed to a N gauge ft i f csssing of Thorium metalhard rod. The physical properties of the wire are as fol- The melt is processed to a No. 10 gauge soft wire I from hard rod. The physical properties of the wire are as "Y i iiigiiilfifiilfc$225220" 5123. Ultimate Tensile Strength 18,500 ps1 10 Conductivity 59 LACS Percent Ultimate Elongation 19% Conductivity 591% IACS ADDITIONAL EXAMPLES EXAMPLE 4 Additional alloy melts are prepared according to Ex- An additional alloy melt is prepared according to Example No. 1. The composition and the physical properample No. 1 so that the composition is as follows in ties of No. 10 gauge soft wire from hard rod of the alloy weight percent: melts are as follows:

TABLE 2 lACS Example No. Co Ni Mg UTS in psi Elongation Conductivity W 030% Through testing and analysis of an alloy containing 838;; 0.80 weight percent cobalt, 0.30 weight percent nickel, Tantalum 0.20% and the remainder aluminum, it has been found that the Alumnum present aluminum base alloy after cold working includes an intermetallic compound precipitate. The compound is identified as cobalt aluminate (Co Al The melt is processed to a No. 10 gauge soft wire from i cobalt w wfi i g i fi f 2: very h rd rod. The h sical ro erties of the wire are as fol- Stdble and espccll y 50 tbmpcrltun's' a p y p p pound also has a low tendency to coalesce during anlows: nealing of products formed from the alloy and the compound is generally incoherent with the aluminum maummmc Tensile strength 19,380 psi trix. The mechanism of strengthening for this alloy is in Percent Ul Elongation 195% 40 part due to the dispersion of the cobalt intermetallic cmducmmy 591% compound as a precipitate throughout the aluminum matrix. The precipitate tends to pin dislocation sites EXAMPLE N() 5 which are created during cold working of the wire formed from the alloy. Upon examination of the cobalt intermetallic compound precipitate in a cold drawn add't'onal alloy melt preprfid aPcOrdmg to wire, it is found that the precipitates are oriented in the amPle 1 so that the composlt'on as follows m direction of drawing. in addition, it is found that the We'ght Percent? precipitates are rod-like or plate-like in configuration and a majority are less than 2 microns in length and less Cobalt 0.60% man micro? h" Nickel 0.35% A characterlstlc of high conductlvity alumlnum alloy E PP 8&2: wires which is not indicated by the historical tests for ifii R'emainde, tensile strength, percent elongation and electrical conductivity is the possible change in properties as a result The melt is processed to a No. 10 gauge soft i f of increases, decreases or fluctuations of thetemperahard rod. The physical properties of the wire are as follure of the Strands- It pp that the maximum P- lows: erating temperature of a strand or series of strands will be affected by this temperature characteristic. The characteristic is also quite significant from a manufac- Ullimate Tqnsile Strength 17900 P turing viewpoint since many insulation processes regifgg g i Elongam" @3 33: ACS quire high temperature thermal cures.

It has been found that the aluminum alloy wire of the present invention has a characteristic of thermal stabil- EXAMPLE 6 ity which exceeds the thermal stability of other aluminum alloy wires. in order to demonstrate this feature a An additional alloy melt is prepared according to ExampleNo. 1 so that the composition is as follows in weight percent:

group of wires is prepared for testing decrease in tensile and yield strength in response to ageing at established temperatures and times. The samples have composiimum conductivity of 57% IACS consisting essentially hot rolling; drawing to flat magnet wire with'no intermediate anneals and then partially annealed.

' The results ofthe test are reproduced in the following of from about 0.20 to about 1.60 weight percent cobalt,

table: from about 0.30 to about 1.30 weight percent nickel,

TABLE 1V 160C-AGE1NG TEMP. 190200C AoEiNG TEMP. SAMPLE TIME DECREASE 1N DECREASE 1N UTS TIME DECREASE 1N DECREASE 1N UTS Y YS No. 1 100 hrs. 0 100 hrs. 600 psi 1200 psi 500 11's. usoopsi 0 670'hrs. 4.200 psi 1200 psi .190 hrs. 0 0 100 hrs. 2.700 psi 2300 psi 500 11S.. 1.800 psi 0. 550 hrs. 9.300 psi 5000 psi No. 3 100 hrs. 1,400 psi 0 V .N o T E s T "TZ86 his. 2.800 P 0 No. 4 100 hrs. 0 0

500 hrs. 0 0 550 hrs. 0 w 0 Y5 Yield Strength UTS Ultimate Tensile Strength A significant aspect shown by the resultsof these tests is the lack of thermal stability obtainable with several aluminum alloys. Thetest sample wires identified as No. 2 and 3 show a significant decrease in thermal stability in the yield and tensile strength tests and alloy No. 2 has almost completely softened after a 550 hour soak period at l902'00 C. On thev other hand, the

wire fabricated from the present alloy demonstrates a high degree of thermal stabilitybyexhibiting zero decreases in yield andtensile-strength.

For the purpose-of. clarity, the following terminology used in this applicationris explained as follows:

Aluminum alloy rod A solid product that is long in relation to its cross section. Rod nonnally has a cross-section ofbetween 3 inches and 0.375 inches-P Aluminum alloy wire A solid wrought product that is long in relation to its cross-sectiomwhich is square or rectangular with sharp or rounded corners or edges, or isround, a regular h'exagonor a regular octagon, and whose diameter or greatest perpendicular distance between parallel faces is between 0.374- inches and the remainder being aluminum with associated trace elements, said aluminum alloy electrical conductor having the following properties when measured as a No. 10 A.W.G. fully annealed wirc:

Tensile strength Elongation Yield strength 12,000 24,000 psi 12% 30% 8.000 18,000 psi 2. Aluminum alloy electrical conductor of claim 1, further including an additional alloying element selected from the group consisting of magnesium and iron, in an amount ranging from 0.001 to 1.0 weight percent.

3. Aluminum alloy electrical conductor of claim 1, further including iron as an additional alloying element in an amount ranging from about 0.1% to about 0.5%.

4. Aluminum alloy electrical conductor of claim 1, further including magnesium as an additional alloying element in an amount ranging from about 0.1% to about 0.5%;

5. Aluminum alloy electrical conductor according to claim 1, wherein the'weight percentages of the constituents are as follows:

Cobalt 0.80% Nickel 0.50% Misch Metal 1.0% Aluminum remainder 6. Aluminum alloy electrical conductor according to claim 1 wherein the weight percentages of the constituents are as follows:

Cobalt 0.80% Nickel 0.40% Niobium 0.20% Tantalum 0.20% Aluminum remainder 7. Aluminum alloy electrical conductor according to claim 1 wherein the weight percentages of the constituents are as follows:

Cobalt 0.60% Nickel 0.35% Copper 0.20% Silicon 0.18% Aluminum remainder 8. Aluminum alloy electrical conductor according to claim 1 wherein the weight percentages of the constituents are as follows:

Cobalt 0.80% Nickel 0.45% Zirconium 0.30% Aluminum remainder 9. The aluminum alloy electrical conductor of claim 1 wherein said conductor is in the form of a rod.

10. The aluminum alloy electrical conductor according to claim 1 wherein said conductor is in the form of a wire.

11. Method of preparing an aluminum alloy conductor having a minimum conductivity of at least 57% lACS comprising the steps of:

A. alloying from about 0.20 to about 1.60 weight percent cobalt with about 0.30 to about 1.30 weight percent nickel, the remainder being aluminum with associated trace elements;

B. casting the alloy in a moving mold formed between a groove in the periphery of a rotating casting wheel and a metal belt lying adjacent said groove for a portion of its length;

Tensile strength Elongation Yield strength 12.000 24,000 psi 12% 30% 8.000 l8.000 psi 12. Method of preparing an aluminum alloy conductor in accordance with claim 11 including the further step of drawing said conductor through wire-drawing dies, without annealing the conductor between drawing dies, to form wire.

13. The method according to claim 11 wherein the alloying step also includes the addition of alloying agents taken from the group consisting of iron and magnesium, in an amount ranging from 0.001 to 1.0%, by weight.

14. The method according to claim 13 wherein said additional alloying element is iron in an amount ranging from about 0.1% to about 0.5%, by weight.

15. The method according to claim 13 wherein said additional alloying element is magnesium in an amount ranging from about 0.1% to about 0.5%, by weight.

16. The method according to claim 11 wherein the alloying step also includes the addition of magnesium in an amount sufflcient to yield an alloy having the following weight percentages:

Cobalt 0.60% to 0.80% Nickel 0.45% to 0.65% Magnesium 0.03% to 0.10% Aluminum 97.8% to 99.20%

17. The method according to claim 11 wherein the alloying step also includes the addition of iron in an amount sufficient to yield an alloy having the following weight percentages:

Cobalt 0.60% to 0.80% Nickel 0.45% to 0.65% Iron 0.03% to 0.10% Aluminum 97.8% to 99.20%

18. The method according to claim 11 wherein the alloying step also includes the addition of misch metal in an amount sufficient to yield an alloy having the following weight percentages:

Cobalt 0.80% Nickel 0.50% Misch metal 1.0% Aluminum remainder 19. The method according to claim 11 wherein the alloying step also includes the addition of niobium and tantalum in an amount sufficient to yield an alloy having the following weight percentages:

Cobalt 0.80% Nickel 0.40% Niobium 0.20% Tantalum 0.20% Aluminum remainder 20. The method according to claim 11 wherein the alloying step also includes the addition of copper and silicon in an amount sufficient to yield an alloy having the following weight percentages:

Cobalt 0.60% Nickel 035% Copper 0.20% Silicon 0.18% Aluminum remainder 21. The method according to claim 11 wherein the alloying step also includes the addition of zirconium in an amount sufficient to yield an alloy having the following weight percentages:

Cobalt 0.80% Nickel 0.45% Zirconium 0.30% Aluminum remainder .22. Aluminum alloy electrical conductor of claim] wherein the weight percentage of the constituents are as follows:

Cobalt 0.60% to 0.80% Nickel 0.45% to 0.65% Magnesium 0.03% to 0.10% Aluminum 97.8% to 99.20%

23. Aluminum alloy electrical conductor of claim 1 wherein the weight percentages of the constituents are as follows:

Cobalt 0.60% to 0.80% Nickel 0.45% to 0.65% Iron 0.03% to 0.10% Aluminum 97.8% to 99.20%

24. Aluminum alloy rod of claim 9 wherein the weight percentages of the constituents are as follows:

Cobalt 0.60% to 0.80% Nickel 0.45% to 0.65% Magnesium 0.03% to 0.10% Aluminum 97.8% to 99.20%

25. Aluminum alloy rod of claim 9 wherein the weight percentages of the constituents are as follows:

Cobalt 0.60% to 0.80%

Nickel 0.45% to 0.65%

Iron 0.03% to 0.10%

Aluminum 

2. Aluminum alloy electrical conductor of claim 1, further including an additional alloying element selected from the group consisting of magnesium and iron, in an amount ranging from 0.001 to 1.0 weight percent.
 3. Aluminum alloy electrical conductor of claim 1, further including iron as an additional alloying element in an amount ranging from about 0.1% to about 0.5%.
 4. Aluminum alloy electrical conductor of claim 1, further including magnesium as an additional alloying element in an amount ranging from about 0.1% to about 0.5%.
 5. Aluminum alloy electrical conductor according to claim 1, wherein the weight percentages of the constituents are as follows:
 6. Aluminum alloy electrical conductor according to claim 1 wherein the weight percentages of the constituents are as follows:
 7. Aluminum alloy electrical conductor according to claim 1 wherein the weight percentages of the constituents are as follows:
 8. Aluminum alloy electrical conductor according to claim 1 wherein the weight percentages of the constituents are as follows:
 9. The aluminum alloy electrical conductor of claim 1 wherein said conductor is in the form of a rod.
 10. The aluminum alloy electrical conductor according to claim 1 wherein said conductor is in the form of a wire.
 11. Method of preparing an aluminum alloy conductor having a minimum conductivity of at least 57% IACS comprising the steps of: A. alloying from about 0.20 to about 1.60 weight percent cobalt with about 0.30 to about 1.30 weight percent nickel, the remainder being aluminum with associated trace elements; B. casting the alloy in a moving mold formed between a groove in the periphery of a rotating casting wheel and a metal belt lying adjacent said groove for a portion of its length; C. hot rolling the cast alloy substantiaLly immediately after casting while the cast alloy is in substantially that condition as cast to form a continuous rod; said aluminum alloy conductor having the following properties when measured as No. 10 A.W.G. fully annealed wire:
 12. Method of preparing an aluminum alloy conductor in accordance with claim 11 including the further step of drawing said conductor through wire-drawing dies, without annealing the conductor between drawing dies, to form wire.
 13. The method according to claim 11 wherein the alloying step also includes the addition of alloying agents taken from the group consisting of iron and magnesium, in an amount ranging from 0.001 to 1.0%, by weight.
 14. The method according to claim 13 wherein said additional alloying element is iron in an amount ranging from about 0.1% to about 0.5%, by weight.
 15. The method according to claim 13 wherein said additional alloying element is magnesium in an amount ranging from about 0.1% to about 0.5%, by weight.
 16. The method according to claim 11 wherein the alloying step also includes the addition of magnesium in an amount sufficient to yield an alloy having the following weight percentages:
 17. The method according to claim 11 wherein the alloying step also includes the addition of iron in an amount sufficient to yield an alloy having the following weight percentages:
 18. The method according to claim 11 wherein the alloying step also includes the addition of misch metal in an amount sufficient to yield an alloy having the following weight percentages:
 19. The method according to claim 11 wherein the alloying step also includes the addition of niobium and tantalum in an amount sufficient to yield an alloy having the following weight percentages:
 20. The method according to claim 11 wherein the alloying step also includes the addition of copper and silicon in an amount sufficient to yield an alloy having the following weight percentages:
 21. The method according to claim 11 wherein the alloying step also includes the addition of zirconium in an amount sufficient to yield an alloy having the following weight percentages:
 22. Aluminum alloy electrical conductor of claim 1 wherein the weight percentage of the constituents are as follows:
 23. Aluminum alloy electrical conductor of claim 1 wherein the weight percentages of the constituents are as follows:
 24. Aluminum alloy rod of claim 9 wherein the weight percentages of the constituents are as follows:
 25. Aluminum alloy rod of claim 9 wherein the weight percentages of the constituents are as follows:
 26. Aluminum alloy electrical conductor having a minimum conductivity of 57% IACS consisting essentially of from about 0.20 to about 1.60 weight percent cobalt, from about 0.30 to about 1.30 weight percent nickel, the remainder being aluminum with associated trace elements, said aluminum alloy electrical conductor having the following properties when measured a a fully annealed wire: Tensile strength: at least 12,000 psi Yield strength: at least 8,000 psi. 